1. Field of the Invention
The present invention relates to a laser apparatus.
2. Description of the Related Art
Some component parts used in laser apparatuses become shorter in lifetime if used at a high temperature. Conversely, if the temperature becomes too low, the characteristics of the laser are able to change. For this reason, in general, the temperature is controlled so that the component parts are maintained at a predetermined temperature of 15° C. to 30° C. in range.
When a laser apparatus is used in a high temperature, high humidity environment, due to the temperature difference between the outside air and the component parts which are maintained at a low temperature, condensation sometimes forms. In particular, if condensation forms at an optical part, it causes the laser light to be absorbed or scattered and the desired performance can no longer be realized. Further, if dust or volatile matter or other foreign matter adheres to a location where condensation forms, after drying, the foreign matter will stick on the surface of the optical part and therefore the optical part will have to be replaced or repaired. Condensation also increases the risk of electric shock or short-circuiting, so is not desirable for electrical parts.
Known in the art are various techniques for preventing the formation of condensation at optical parts. Known in the art is a laser oscillator including a dehumidifier supplying dry air to the inside of the housing holding optical parts etc. (see Japanese Patent Publication No. 04-356981A, Japanese Patent Publication No. 2012-024778A, and Japanese Patent Publication No. 2013-239696A). Known in the art is also a laser oscillator designed to adjust the temperature of optical parts by heating the cooling water for cooling optical components in accordance with need (see Japanese Patent Publication No. 01-232779A, Japanese Patent Publication No. 57-045988A, and Japanese Patent Publication No. 04-335585A).
Also known in the art is a laser oscillator designed to stop the supply of coolant cooling an optical part at the time of stopping emission so as to prevent the formation of condensation (see Japanese Patent Publication No. 2003-110174A).